From the UK - A Simple Scan with the wrong results?

DAVEYLIBRA

Hi, I hope someone can help with this-
I have used the basic scan builder to try to do this-
Scan for major LSE shares, that have shown a new Elder Red bar for the end of day.
The high must also be below the EMA (65).

I have attached the criteria that stockcharts.com wrote out for me- however, from the results, ITV had blue Elder bar at end of
day, not red. Further scans have also given results where not all end of day bars are red.

Could this be something to do with timing, as they are UK shares? I scan at least 3-4 hours after close of trading, which is 4.30pm UK time.
And this shouldn't be a problem, as the scan is in real time, and shouldn't possibly return anything but red bars!

I used the drop down box from the builder, to say Elder Red Bar is true for 0 days ago.

Must be something I am doing wrong, as I am new to this!

gord

Dave I did send in a detailed problem report and I did get a response back late last night. They are aware of the problem and working on a resolution, but it may take a couple of days.

I think this is fully understandable as we are heading into the Easter long weekend and many staff will be on holidays. I'll let everyone know as soon as I hear anything more.

markd

Hi @DAVEYLIBRA , I'm not sure what code the scan engine is producing for you. There is a button below the standard workbench that takes you to the advanced workbench that shows you the actual scan engine code.

In any case, I transcribed the "plain english" conditions, and they seem to work. I set the run date for "last market close", which in this case would be March 22 (actual run time about 9:45 am eastern time (US) March 23).

Note when you get the results, the charts display as of the current moment, not as of the end of the data the scan engine looks at, so the last bar on the chart may or may not be red if there is data after the scan date you set.

Without seeing the advanced scan page as you ran it, I can't explain the apparent error you saw. I suppose it's possible you ran it during the day at a moment when the bar was red but got results when the bar had turned green or blue. I don't actually know the details of how Elder Bar turns red or green or blue, so that's just a guess.

So here's the advanced scan page code that seems to work as you want:


// begin LSE scan

[exchange is LSE]

and [sma(60, close) > 100]
and [sma(65, close) > high]
and [sma(60, volume) > 1000000]

and [Elder Bar Red is true]
and [ 1 day ago Elder Bar Red is false]

// end LSE scan

DAVEYLIBRA

Hi, thanks very much for your help, but I copy & pasted the code above into the advanced scan page. The very 1st result, BT.L shows the last 3 bars as blue! This was at 7.45pm UK time. The market closes at 4.30pm.
Can you see my attachments? I am not sure if they are big enough to view. If so, you can see the code in the first, and the chart in the second....
Having said that, I think that these bars qualify as Elder Red, it it just that they are being sown as the wrong colour. If you see what I mean??

DAVEYLIBRA

Thank you very much for your help, but I copy & pasted your above code into the advanced scanner and the first result, BT.L, shows the last 3 bars as blue! There should be no problem with the time as it is 10.30pm, 6 hours after market close. (I don't know what the delay is on UK charts?)
Can you see the attachments? Not sure if they are big enough?
I must also add that I think these bars qualify as Elder Red, even though they are not coloured red, if you see what I mean. But I am still not sure as to what the problem may be.... ?

gord

Hi Davey welcome to the board.

I just did a few tests on this issue and agree there seems to be something a little off. If I add "rank by elder bar red" at the end of the scan the scan engine returns that they are all "1.00" which is true for Red, but of course we know not all are red. First thing I noticed was the close and volume values on your scan output page are not the same as on the chart you show and I think this is the problem.

It's important to realize the charting database and the scan database are not on the same server. The scan database is smaller and on a very fast server with fast memory, necessary to run scans in a few seconds, it would take several minutes or hours to run a scan using the much larger and slower charting database. This should make sense as when pulling up a chart you are only retrieving data for on symbol, not 10's of thousands at a time.

I think the problem is the timing of when the databases are updated, intraday or current day seems to be a problem, but if I run the scan for 1 or more days ago the results are correct.

Best option here is for you to send in a request to StockCharts thru the support page tab detailing the problem. I'll do the same thing.

Gord

DAVEYLIBRA

OK thanks. Actually I could just put in the parameters for Elder bars, (I believe it is just a MACD and an EMA), have these on my charts and it would show if everything is correct, I just wouldn't have the colours. But thanks for looking into it!